%0 Journal Article
%T 下行移动床颗粒流动特性冷模试验研究
%A 卢啸风
%A 李建波
%A 杨帆
%A 王泉海
%A 薛景文
%A 郑雄
%A 陆凯
%J 洁净煤技术
%D 2019
%X 针对目前大宗固体颗粒余热回收常存在换热不充分、气固流动阻力大、回收得到的余热质量较低等问题,提出了一种气固交叉流动移动床高温颗粒冷却技术方案,并在自行设计的工业级试验装置上利用CFB锅炉炉渣完成了冷态条件下的颗粒流动特性试验研究。通过取样与高速摄影仪拍摄相结合的方式对颗粒流动特性进行测量,分析讨论了颗粒流通截面尺寸对颗粒流动特性的影响和错流段空截面风速对颗粒流动稳定性的影响。结果表明:直流段截面中部颗粒下行速度基本一致,在忽略边壁影响的条件下,计算得到直流段正面和侧面流动指数MF1均大于0. 3,认为直流段颗粒流动为整体流状态;通过对不同位置颗粒取样,发现各取样点颗粒的质量分数最大相差约14. 4%,在实际工程中可认为扩大段颗粒整体流动均匀,但不同位置的颗粒粒径分布存在差异;随着横向风速的增大,颗粒携带速率增大,流过下行移动床的水平风速不能超过1. 45 m/s。 In terms of the problems that exsit in the waste heat recovery of bulk solid particles,such as insufficient heat transfer,high gas-solid flow resistance and low quality of the waste heat recovery,a cooling technology for high temperature particle using gas-solid cross-flow moving bed was proposed in this study.The experimental study on particle flow characteristics under cold operating conditions was carried out with CFB boiler ash via a self-designed industrial experimental apparatus.Particle flow characteristics were measured by sampling and high-speed photography.The effects of the cross-sectional size of the particle flow on particle flow characteristics and cross-sectional gas speed on particle flow stability were analyzed and discussed.The results show that the downward velocity of particles in the central part of the straight flow section is basically constant.Neglecting the influence of the side walls,the calculated flow index MF1 of the front and side section of straight flow section exceed 0.3,which show that the particle flow was considered as a bulk flow under the experimental conditions.By sampling the particles at different locations,it is found that the maximum difference of particle mass ratio is about 14.4%,which could be considered that the particle flow in the enlarged section was uniform in practical engineering,while the particle size distribution at different locations is different.With increasing the transverse air velocity,the particle carrying rate increases.The air velocity in the downward moving bed can not exceed 1.45 m/s
%K 移动床
%K 颗粒流
%K 流动特性
%K 冷模试验 moving bed
%K granular flow
%K flow characteristic
%K experimental study
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